Thursday, January 16, 2020

Product Review : Retro-bit's Metal Storm NES Re-release

Reproductions of NES games are nothing new, people have been making them and selling them illegally for years.  Recently the retro gaming market has shown such strength and durability that legitimate companies have felt there was sufficient interest in making new copies of original games.  These games would come packaged as "Anniversary Editions" or "Collector's Editions" and come in packaging and with extras that would easily eclipse the original game's.  This of course requires contacting the rights holder and negotiating for permission to release more copies of their game.  Recently, the relatively uncommon but well-regarded NES game Metal Storm received a release from retro-bit and I had the chance for it to come into my possession, so let me use this blog entry to review the game and explain why I had the opportunity to briefly handle it.

I have often in conversation referred to retro-bit as one of the "Four Horsemen of the Retro-Gaming Apocalypse", one of four well-known companies (Hyperkin, atgames and Gamerz-Tek) that have consistently released garbage retro video game products over the years.  They are hardly alone among lousy retro gaming product makers, but they are the most prominent.  Hyperkin can put out a decent controller, so I guess it has graduated, just barely, from the "Horsemen".  Can retro-bit do the same with its release of Metal Storm?  Let's find out.

The Game

Metal Storm is an interesting NES side-scroller from 1991.  It is notable for its gravity-flipping game mechanic.  When you flip upwards, you will walk upside down on the "ceiling."  Flipping downards will let you walk back on the "ground."  The game integrates this mechanic rather well into what could have been little more than a Robotech-inspired platforer.  The game did not sell in huge numbers, hence it going for rather high prices for a bare cartridge these days.  Reproductions of games from companies like iam8bit reproduced rather common cartridges like Street Fighter II and Mega Man X for the SNES.  This may be the first time you can fill a hole in your NES collection for a price ($44.99 for Standard Edition, $69.99 for Collectors Edition) for less than the cost of the original game.

Rear of the Standard Edition Box
One of the big draws of this retro-bit version is that it is based on the Japanese version, which was released after the U.S. version.  This is unusual given that the game was developed in Japan (by Tantex) and released by Irem in both parts of the world.  The US version has no introductory sequence in the game, it shows you the title screen followed by an attact mode showing gameplay.  The Japanese version tells the story of the game with five screens of text and six animations and displays the credits.  The English version eliminated this introduction and the opening credits.  The English version also changed the color of the M-308 from white to orange and the background colors and lowers the difficulty compared to the Japanese version.  The retro-bit release is based on the Japanese version with its color scheme, introduction and credits.  Japanese passwords work on it, U.S. passwords do not.  The final boss battle and the ending text is changed from the U.S. to the Japanese version.

This is not the first time that Metal Storm's Japanese release has been translated.  An unofficial translation was released in 2009.  The official translation was a little bit more ambitious than the unofficial translation.  The unofficial translation reverts the colors to the U.S. version for some strange reason.  The unofficial translation does not change the hardware from the untranslated version, but as we will see, the official translation does, sort of.  Here is one of the opening text screens from the introduction to the game.  You can see that the unofficial translation uses the same font as the credits naming the Japanese developers, while the official translation uses larger and thicker characters more reminiscent of the original Japanese kana and kanji.

Original Japanese - Unofficial Translation - Official Translation
The Product

When I received a copy of the Standard Edition from Castlemania Games, I was impressed by the quality of the packaging.  The box was NES-sized and had appropriate shiny accents.  It displayed that the game was licensed from Irem.  Opening the box found a manual, a dust sleeve and dual-sided poster.  The poster and the manual were in full-color, and the manual was dual English/Japanese language.  So far, so good.  Europe will receive slightly different Collector and Standard editions, but the game will run at NTSC speeds.  This is a shame, not all our European brethren have NTSC compatible NESs or Famicoms.  

Next we come to the cartridge.  The Standard Edition has a NES cartridge shell in blue opaque plastic.  The cartridge label is glossy and feels like quality, although only time will tell how durable it is.  The cartridge is enclosed with Nintendo security screws like original NES cartridges came with after 1987.  Opening it up reveals the PCB containing the game :

Retro-bit version PCB Front
The hardware on the retro-bit board is very different.  First, there is a 2MiB PRG-ROM.  Second, there is 2 x 128KiB RAM chips.  Third, there is a SMD133 ASIC chip with a pair of TTL chips.  An Amtel ATiny13A provides a lockout chip clone for front loading NESs.  I asked a friend of mine who designs PCBs what he thought of the quality of the PCB.  His opinion was decidedly mixed.  He observed that U11 and U12 were hand-soldered and that the flash chip at U2 was not a new part but a pull from another device.  He informed me that a 2MiB or even a 1MiB flash chip using 5v logic cannot be procured new in quantity.  He also believes that the solder mask should overlap the cartridge pins to better protect the connection and traces from corrosion as Nintendo always did.  The RAM and the generic TTL chips are also 5v parts.  There is no voltage regulator installed at U7, so it is likely that the SMD133 has 5v tolerant I/O.

The original Metal Storm used a common MMC3 TLROM board in its Japanese and English releases.  The PRG-ROM was 128KiB and the CHR-ROM was 256KiB.  The retro-bit PCB uses the same ASIC as the large COOLBOY and MINDKIDS multicarts, emulated as NES 2.0 Mapper 268.

The 2 MiB flash PRG-ROM chip contains the same 512 KiB of data, which is repeated three times. That 512 KiB contains the 256 KiB of pattern/graphics data, 128 KiB of game code, 96 KiB of padding, and 32 KiB of loader code. The loader copies the 256 KiB of pattern data to CHR-RAM, then transfers control to the 128 KiB of game code, setting the ASIC into such a state as if the game ran on a Nintendo 128 KiB+256 KiB TLROM board.  The process of copying the pattern data into CHR-RAM takes about two to three seconds.  The original cartridges use CHR-ROM and do not have the extra loading pause on bootup.

In the original US and Japanese releases of Metal Storm, to flip the gravity toward the top of the screen you press Up and A and to flip the gravity toward the bottom of the screen you press Down and A.  You can reverse the direction of the D-pad required for the flip, so that Up and A flips down and Down and A flips up, by pausing the game with Start and holding Select as you press Start to unpause the game.  The controls are reversed each time you do this Start, Select + Start  procedure.

In the retro-bit version, due to this loader code utilizing memory locations later used by the game, the controls are reversed from the original versions by default.  So when you start the game, Up and A flips down and Down and A flips up.  Several people have complained that this scheme is counter-intuitive.  Extracting the 128 KiB of game code and 256 KiB of pattern data, and running this extracted game as MMC3, will restore the original default setting.


One assumes that retro-bit decided to use Mapper 268 to protect its version of the game.  Unfortunately, by relying on the less than stellar quality Chinese board, they negatively impacted the quality of their product in ways noticeable to the player.

Overall, however, this release has resulted in a good quality product.  The game itself was a good choice, somewhat obscure but with solid gameplay mechanics.  The packaging is good quality and the PCB is passable.  The price for the Standard Edition is not ridiculous given you get a complete release, not just a bare cartridge.  The flaws can be fixed (but don't expect a release while this version is being sold).  I declare that retro-bit has graduated from the Horsemen.  That does not put them on the Analogue or 8bitdo level or anywhere near it, but you can buy one of their products without setting yourself up for disappointment.


  1. Fantastic writeup! I'm glad I found your review otherwise I would have never known that you could change the gravity with select and start. That is not even in the manual. Also, it does seem they were successful since I haven't found a way to dump the cart with my kazzo. Would love to be able to make a backup.

    1. You can try the standard MMC3 scripts, but I doubt it will be successful. I have been informed by people more knowledgeable than myself that the kazzo in its current state will never be able to dump the retro-bit cartridge. The reason for this is that the Mindkids mapper needs an M2 clock signal properly aligned to the ROM enable signals, and the kazzo does not provide this. In short, the kazzo is not a sound design to dump new cartridges.

    2. Hello!

      What method is the recommended way to dump this and other games that use the MINDKIDS board? I have Rainbow Brite cart and I can't dump it with the INL Retro Dumper/Programmer. Originally, I read someone made a script to make it work, but I have no idea how or where the script is...if it exists.

      If there is a good dumper for it, that would be great. I can save up for it.


    3. You need a CopyNES to dump the cartridge. Accept no second-rate substitutes like the INL Retro Dumper.

    4. Hi again,

      I managed to get the CopyNES and will install it soon. What method did you use? Like what steps? What about the mapper and/or script? Thanks!!!

    5. CopyNES uses a script composed of 6502 assembly commands. You must use the information from the Mapper 268 page on the NESDev wiki to write a script to dump games like these.

    6. I'm trying, but no luck. I've gone to the NESDEV site, but since I'm still new, I don't understand what to do. CloneNES doesn't seem to have the correct plugin either. And I've tried searching online for plugins with no luck.

      I know the addresses used by CloneNes, I just don't know how to write a script/plug-in.

      Do you know, if possible, where to obtain the proper plugins? I really want to play my games on my cellphone, particularly Rainbow Brite, Metal Storm, and the Retrobit Collection. :(

  2. So, in your opinion is it worth getting this release over the original US or Japanese versions (assuming price is out of the equation)? I never did get Metal Storm and have been debating on this release or one of the originals. I do like the font in the retro bit version - reminds me of the Quintet SNES releases which are some of my all time favorites.

    1. Yes, I believe it is worth it even if the cartridge PCB is something of a diamond in the rough.

  3. this just seems like intellectual property theft with extra steps